respiration

[res-puh-rey-shuhn]

noun

1. the act of respiring; inhalation and exhalation of air; breathing.

2. Biology.

   1. the sum total of the physical and chemical processes in an organism by which oxygen is conveyed to tissues and cells, and the oxidation products, carbon dioxide and water, are given off.

   2. an analogous chemical process, as in muscle cells or in anaerobic bacteria, occurring in the absence of oxygen.

respiration

/ ˌrɛspəˈreɪʃən /

noun

1. the process in living organisms of taking in oxygen from the surroundings and giving out carbon dioxide ( external respiration ). In terrestrial animals this is effected by breathing air

2. the chemical breakdown of complex organic substances, such as carbohydrates and fats, that takes place in the cells and tissues of animals and plants, during which energy is released and carbon dioxide produced ( internal respiration )

respiration

1. The process by which organisms exchange gases, especially oxygen and carbon dioxide, with the environment. In air-breathing vertebrates, respiration takes place in the lungs. In fish and many invertebrates, respiration takes place through the gills. Respiration in green plants occurs during photosynthesis.

2. See cellular respiration

respiration

1. The conversion of oxygen by living things into the energy by which they continue life. Respiration is part of metabolism.

Carbon dioxide is a waste product of respiration.

Other Word Forms

• respirational adjective
• prerespiration noun

Word History and Origins

Origin of respiration¹

1400–50; late Middle English respiracioun < Latin respīrātiōn- (stem of respīrātiō ) a breathing out, equivalent to respīrāt ( us ) (past participle of respīrāre to respire ) + -iōn- -ion

Example Sentences

Microorganisms drive nearly every step of these processes, using substances like sulfur and iron for respiration in much the same way humans rely on oxygen to metabolize food.

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The study, titled "Leucine inhibits degradation of outer mitochondrial membrane proteins to adapt mitochondrial respiration," was published in Nature Cell Biology.

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Birds are particularly susceptible because they have a high respiration rate, and it causes them stress to keep them kenneled indoors.

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The researchers hope that the findings of this work pave the way to more innovation in the methods used to monitor vital signs in captive animals, including heart rate and respiration rate.

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This natural process, known as microbial respiration, is what produces the carbon dioxide and methane emissions forecasted by climate modelers.

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